GP lens eye Rounds

MYOPIA MANAGEMENT: Case: Moderate Unilateral Myopic Child Ortho-K

Sheila Morrison OD, MSc, FAAO, FSLS

History

• Chief Complaint: 14-year-old female with average myopic progression over four years of approximately 0.50D/year. The patient is a competitive gymnast. Mother self-referred for myopia control.
• Family refractive history: mother and father low bilateral hyperopic astigmatism with presbyopia
• Systemic Health: unremarkable
• Ocular history:
  • Intolerance of daily single vision soft lenses due to dry eye discomfort
  • Mild trichiasis upper lid OU
  • Progressive school-age myopia
  • Prior Rx at 10 years old
    • OD: +0.25 -0.75 x 005
    • OS: +1.00 -1.00 x 173

Examination

• Entering visual acuities:
  • Spectacles:
    • OD: 20/20
    • OS: 20/20
• Cycloplegic refraction:
  • • OD: -2.00 -1.00 x 180, 20/20
    • OS: -0.25 -1.00 x 180, 20/20
• Slit lamp Examination:

• Corneal Topography (Figure 1):

• Axial Length (Figure 2)

• Dilated Fundus Examination: posterior ocular health WNL

Decision-Making Process

Positive risk factors for myopic progression in this case include being outside the age norm for refractive error and axial length OD > OS. Environmental and lifestyle factors (i.e. screen use) are also considerations. The patient is a candidate for all therapies: myopia control spectacles, daily wear contact lenses, orthokeratology (better candidate OD than OS), and atropine (alone or adjunct). Based on ~1:1 ratio of myopic refractive error to control effect in diopters, the right eye is a good candidate for ortho-k; OS (largely astigmatic power only) is more difficult to correct and may provide less myopia control. Age (older) and parental refractive error (not minus) are lower risk factors. Ortho-k was chosen OU, as the patient is active and preferred freedom from spectacles; history of dry eye with daily wear lenses.

Fitting and Evaluation

• Ortho-K lenses were designed empirically from topography, HVID and refraction, with a Jessen Factor of +0.50D.
• First dispense: Lens centered, with good movement and coverage of the pupil axis. Edges slightly tight. ORx: +0.25DS OD/OS/OU, VA: 20/20 OD/OS/OU
• One day follow-up visit: OD lens slightly adhered with trace edge corneal staining on removal. Education provided on solutions and handling, also ensuring lid technique is used and lenses mobile before removal. Adequate centration and full treatment OU. 20/20 OD/OS/OU.
• One Week follow-up visit: Adequate centration (Figure 3a left) and full treatment OU. 20/20 OD/OS/OU. Central adhesion staining OD only (Figure 3b right), OS cornea clear. OD lens placed back on eye, tight edges observed. Plan: adjust OD only with PC 1 step flatter; dispense without appt, RTC four weeks to follow for ortho-k follow-up.

Figure 3: Lens with tight edges and post-wear central adhesion staining OD(Images courtesy of Dr. Alia Cappellani)

• One month follow-up visit: Adequate treatment centration and full treatment (Figure 4). 20/20 OD/OS/OU. Corneas OU clear. Patient is satisfied. Plan: Finalized lenses, RTC six months for ortho-k/myopia control follow-up, sooner PRN.

Figure 4: Axial Power Difference Display Map OD Axial Power Difference Display Map OS

• Six month follow-up: stable, healthy, with no myopic progression (Figure 5). Continue ortho-k with no adjunct atropine treatment.

Figure 5: Axial Power Difference Display Map OD Axial Power Difference Display Map OS

Clinical Pearls

• Ortho-K is a viable option for myopia management in school-aged patients with dry eye or ocular allergies that cause discomfort with soft contact lenses
• Solutions and handling are the most common cause for lens adhesion; ensuring that a lens fit is appropriate also is necessary for safety and performance of ortho-k lenses
• Genetics is often a strong predictor of myopia; however, patients may be myopic with parents that are not, and vice versa.

Beneficial Resources

1. The International Myopia Institute: https://myopiainstitute.org/imi-white-papers-clinical-summaries/
2. Lipson MJ. (2019). Contemporary Orthokeratology. Retrieved from https://contemporaryorthokeratology.com/